An analyzer for automatically analyzing the cells of a subject and providing information pertaining to canceration of the cells is known (for example, refer to US Patent Application publication No. 2008/0108103 and Japanese Patent Laid-open Publication No. 2004-286666). US Patent Application publication No. 2008/0108103 discloses a device that flows a measurement sample including cells collected from a subject to a flow cell, irradiates the measurement sample flowing through the flow cell with light to acquire a scattered light signal for the individual cell, extracts a characteristic parameter by analyzing the waveform of each scattered light signal, and discriminates cancer/atypical cell from a plurality of cells using the characteristic parameter.
Japanese Patent Laid-open Publication No. 2004-286666 discloses a device for supporting pathological diagnosis: capturing an image of cells flowing through a flow cell; estimating the distribution of the nucleus and cytoplasm from the acquired image data; and estimating the distribution of cancer sites in a pathological specimen based on a ratio (N/C ratio) of the area of the estimated distribution of the nucleus and cytoplasm.
For example, in the tissue diagnosis of the uterine cervix, the process from the normal state to cancer has a plurality of stages, “Normal”, “CIN1”, “CIN2”, “CIN3”, and “Cancer” in order from the normal state. Among them, the stages, “CIN1”, “CIN2”, and “CIN3 ” are in the stage called “cervical intraepithelial neoplasia (CIN)”.
“CIN1” is a state in which the atypical parabasal cells are growing in one third from a basal layer to a surface layer, and is a state in which the possibility of regressing spontaneously is high. Thus, treatment is determined as unnecessary in “CIN1”. “CIN2” is a state in which the atypical parabasal cells are growing in two thirds from the basal layer to the surface layer. Treatment is determined as necessary in “CIN2”. “CIN3” is a state in which the atypical parabasal cells are growing entirely from the basal layer to the surface layer. Treatment is determined as necessary in “CIN3”. In order to start the treatment for cancer in the initial stage, it is preferable to detect the possibility of cancer in the initial stages of cancer such as “CIN2” and “CIN3 ” before the stage “Cancer”. It is preferable to distinguish between the cell in the stage before the stage “CIN1” determined as unnecessary for the treatment and the cell in the stage after the stage “CIN2” determined as necessary for the treatment.
In the stage “CIN1” determined as unnecessary for the treatment or the stage “CIN2” determined as necessary for the treatment, the normal cells, cancer cells or atypical cells are mixed. Thus, even if the cells are collected from the uterine cervix of a subject of “CIN1” to prepare a measurement sample or the cells are collected from the uterine cervix of a subject of “CIN2” to prepare a measurement sample, the normal cells, cancer cells or atypical cells are mixed in both of the measurement samples. Even if only the atypical cells are detected, it is difficult to detect the possibility of cancer in the initial stage with high accuracy.
Even if a measurement sample prepared by collecting from the uterine cervix of a subject in the initial stage of cancer is analyzed by the analyzer described in US Patent Application publication No. 2008/0108103 and Japanese Patent Laid-open Publication No. 2004-286666, a percentage of the cancer cells or atypical cells in the total number of the cells to be analyzed is decreased. Thus, it is difficult to detect the possibility of cancer in the initial stage with high accuracy.